Device and method for treating vascular occlusion

ABSTRACT

A system and method for managing an occlusion, such as a blood clot, within a lumen or passageway of a patient. More particularly, a system and method for rapidly restoring blood flow through an occlusion including a self-expanding, tubular member through which blood may flow when in an expanded state. The tubular member has a structure configured to engage the occlusive material, thereby allowing for extraction of at least a portion of the occlusive material. The system may further employ a material extraction member that is deployed distally of the tubular member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional applicationSer. No. 14/430,519 filed on Mar. 23, 2015 entitled Device and Methodfor Treating Vascular Occlusion, which is a 35 U.S.C. 371 ofInternational Patent Application No. PCT/US2013/061470 filed on Sep. 24,2013 entitled Device and Method for Treating Vascular Occlusion, whichApplication claims priority to U.S. Provisional Application Ser. No.61/864,356 filed Aug. 9, 2013 entitled Devices and Methods for Treatmentof Vascular Occlusion; U.S. Provisional Application Ser. No. 61/845,796filed Jul. 12, 2013 entitled Devices and Methods for Treatment ofVascular Occlusion; U.S. Provisional Application Ser. No. 61/750,277filed Jan. 8, 2013 entitled Devices and Methods for Treatment ofVascular Occlusion; U.S. Provisional Application Ser. No. 61/728,775filed Nov. 20, 2012 entitled Devices and Methods for Treatment ofVascular Occlusion; and U.S. Provisional Application Ser. No. 61/705,129filed Sep. 24, 2012 entitled Devices and Methods for Treatment ofVascular Occlusion; each of which are incorporated herein by referencein their entireties.

TECHNICAL FIELD

This invention relates to a system and method for endovascular treatmentof blood clots obstructing passageways in the circulatory system.

BACKGROUND

Thromboembolism is the formation in a blood vessel of a clot (thrombus)that breaks loose (embolizes) and is carried by the blood stream toanother location in the circulatory system resulting in a clot orobstruction at that new location. For example, a clot may embolize andplug a vessel in the lungs (pulmonary embolism), the brain (stroke), thegastrointestinal tract, the kidneys, or the legs. Thromboembolism is asignificant cause of morbidity (disease) and mortality (death),especially in adults. A thromboembolism can be sudden and massive or itmay be small and multiple. A thromboembolism can be any size and athromboembolic event can happen at any time.

When a thrombus forms in the venous circulation of the body it oftenembolizes to the lungs. Such a thrombus typically embolizes from theveins of the legs, pelvis, or inferior vena cava and travels to theright heart cavities and then into the pulmonary arteries thus resultingin a pulmonary embolism.

A pulmonary embolism results in right heart failure and decreased bloodflow through the lungs with subsequent decreased oxygenation of thelungs, heart and the rest of the body. More specifically, when such athrombus enters the pulmonary arteries, obstruction and spasm of thedifferent arteries of the lung occurs which further decreases blood flowand gaseous exchange through the lung tissue resulting in pulmonaryedema. All of these factors decrease the oxygen in the blood in the leftheart. As a result, the oxygenated blood supplied by the coronaryarteries to the musculature of both the left and right heart isinsufficient for proper contractions of the muscle which furtherdecreases the entire oxygenated blood flow to the rest of the body. Thisoften leads to heart dysfunction and specifically right ventricledysfunction.

This condition is relatively common and has many causes. Some of themore common causes are prolonged inactivity such as bed rest, extendedsitting (e.g., lengthy aircraft travel), dehydration, extensive surgeryor protracted disease. Almost all of these causes are characterized bythe blood of the inferior peripheral major circulatory systemcoagulating to varying degrees and resulting in permanent drainageproblems.

There exist a number of approaches to treating thromboembolism andparticularly pulmonary embolism. Some of those approaches include theuse of anticoagulants, thrombolytics and endovascular attempts atremoval of the emboli from the pulmonary artery. The endovascularattempts often rely on catheterization of the affected vessels andapplication of chemical or mechanical agents or both to disintegrate theclot. Invasive surgical intervention in which the emboli is removed byaccessing the chest cavity, opening the embolized pulmonary arteryand/or its branches and removing the clot is also possible.

The prior approaches to treatment, however, are lacking. For example,the use of agents such as anticoagulants and/or thrombolytics to reduceor remove a pulmonary embolism typically takes a prolonged period oftime, e.g., hours and even days, before the treatment is effective.Moreover, such agents can cause hemorrhage in a patient.

And the known mechanical devices for removing an embolism are typicallyhighly complex and prone to cause undue trauma to the vessel. Moreover,such known devices are difficult and expensive to manufacture.

Lastly, the known treatment methods do not emphasize sufficiently thegoal of urgently restoring blood flow through the thrombus once thethrombus has been identified. In other words, the known methods focusprimarily and firstly on overall clot reduction and removal instead offirst focusing on relief of the acute blockage condition followed thenby the goal of clot reduction and removal. Hence, known methods are notproviding optimal patient care, particularly as such care relates totreatment of a pulmonary embolism.

SUMMARY

The above described shortcomings of the existing systems and approachesfor treating an occlusion in a lumen of a patient, such as athromboembolism and particularly a pulmonary embolism, are improved uponby the systems and methods of the present invention. These improvementsare achieved in certain embodiments of the present invention, in part,by providing an occlusion management system comprising a catheter, apusher, and a tubular member reversibly restrained in a compressed statewithin a lumen of the catheter and radially expanded from the compressedstate upon retraction of the catheter relative to the pusher.

These improvements are further achieved in certain embodiments of thepresent invention, in part, by providing occlusion management systemcomprising a catheter, a pusher, a tubular member attached to a distalend of the pusher, and an extraction member extending distally of adistal end of the cylindrical member having a diameter larger than adiameter of the cylindrical member.

These improvements are further achieved in certain embodiments of thepresent invention, in part, by a method for management of an occlusionin a lumen comprising the steps of: creating a passage for fluid flowthrough occlusive material in a lumen of a patient, engaging a portionof the occlusive material with at least a portion of a tubular member;and extracting a portion of the occlusive material from the lumen of thepatient.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of which embodiments ofthe invention are capable of will be apparent and elucidated from thefollowing description of embodiments of the present invention, referencebeing made to the accompanying drawings, in which

FIG. 1 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 2 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 3 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 4 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 5 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 6 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 7 is a side elevation view of a portion of an occlusion managementsystem according to one embodiment of the present invention.

FIG. 8 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 9 is a partial cutaway view of a portion of an occlusion managementsystem within a lumen of a patient according to one embodiment of thepresent invention.

FIG. 10 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 11 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 12 is a partial cutaway elevation view of a portion of an occlusionmanagement system according to one embodiment of the present invention.

FIG. 13 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 14 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 15 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 16 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 17 is a partial cutaway view of a portion of an occlusionmanagement system according to one embodiment of the present invention.

FIG. 18 is a partial cutaway view of a portion of an occlusionmanagement system according to one embodiment of the present invention.

FIG. 19 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 20 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 21 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 22 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 23 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 24 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 25 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 26 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 27 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 28A is an elevation view of a portion of an occlusion managementsystem according to one embodiment of the present invention.

FIG. 28B is a partial cutaway view of a portion of an occlusionmanagement system within lumen of a patient according to one embodimentof the present invention.

FIG. 29 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 30 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 31 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 32 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 33 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 34 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 35 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 36 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 37 is a partial cutaway view of a portion of an occlusionmanagement system within a lumen of a patient according to oneembodiment of the present invention.

FIG. 38 is an elevation view of a portion of an occlusion managementsystem according to one embodiment of the present invention.

FIG. 39 is a perspective view of a portion of an occlusion managementsystem according to one embodiment of the present invention.

FIG. 40A-40C are elevation views of portions of an occlusion managementsystem according to one embodiment of the present invention.

DETAILED DESCRIPTION

Specific embodiments of the invention will now be described withreference to the accompanying drawings. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art. Theterminology used in the detailed description of the embodimentsillustrated in the accompanying drawings is not intended to be limitingof the invention. In the drawings, like numbers refer to like elements.

Methods and systems according to the present invention are broadlydirected to treating a blood vessel or other body lumen. Moreparticularly, the present invention is directed to systems and methodsfor disrupting, dissolving, and/or otherwise removing occlusivematerials, such as thrombus, from a treatment site, such as a bloodvessel.

With reference to FIGS. 1-6, in one embodiment of the present invention,an occlusion management system 10 employs a catheter 12 and a flowrestoration member 14. The flow restoration member 14 is radiallyexpandable from a compressed delivery state, to a radially expanded,minimum energy state having at least, in part, a hollow cylindrical ortubular shape. A distal end 18 of a pusher 16 is attached to a proximalportion 20 of the flow restoration member 14.

The flow restoration member 14 may be formed of a porous mesh orscaffold. The mesh or scaffold may be formed at least in part by a braidof filaments or fabricated by methods known in the art of stentmanufacturing including but not limited to conventional machining, lasercutting, electrical discharge machining (EDM) and photochemical etching.

In operation, the pusher 16 and the attached compressed flow restorationmember 14 are inserted into a lumen 22 of the catheter 12. The catheter12 is advanced through a lumen 2 of a patient, e.g. a blood vessel 2, toa site within the lumen 2 at which occlusive material 4, such as athrombus or an embolus, is located. The catheter 12 is advanced in thedirection of arrow 26 through the occlusive material 4 until a distalend 24 of the catheter 12 passes entirely through the occlusive material4, as shown in FIG. 1.

With reference to FIG. 2, the catheter 12 is then retracted relative tothe pusher 16 and flow restoration member 14 in the direction of arrow28. As the flow restoration member 14 is exposed from the retractingdistal end of the catheter 12, the flow restoration member 14 radiallyexpands within the occlusive material 4 to an intermediate diameterlarger than a diameter of the member 14 in the compressed delivery stateand smaller than a diameter of the member 14 in the expanded, minimumenergy state. The structure and outer surface of the flow restorationmember 14 is configured such that the mesh or scaffold of the flowrestoration member 14 engages the occlusive material 4 when it isexposed from the constraint of the catheter 12. As shown in FIG. 2, thecatheter 12 is retracted in the direction of arrow 28 to an extent thatallows for the radial expansion of an entire length of the flowrestoration member 14.

As shown in FIG. 3, when catheter 12 is retracted sufficiently to allowexpansion of the entire length of the flow restoration member 14, fluidor blood may enter the open, proximal portion 20 of the flow restorationmember 14 in the direction of arrows 30, flow through the hollowinterior of the flow restoration member 14, and exit through a open,distal portion 34 of the flow restoration member 14. Thereby, allowingfor a rapid restoration of blood flow through the lumen 2.

As shown in FIG. 4, the pusher 16 is then retracted relative to thecatheter in the direction of the arrow 28, thereby pulling the length ofthe flow restoration member 14 through the occlusive material 4. Thepusher 16 is retracted such that the flow restoration member 14 ispulled towards the distal end 24 of the catheter 12 and back into thelumen 22 of the catheter 12. As the flow restoration member 14 is pulledthrough the occlusive material 4, the occlusive material 4 engaged withthe flow restoration member 14 is also pulled along and removed.

Hence, while restoring flow through the lumen 2, the flow restorationmember 14 may also function to remove or extract at least a portion ofthe occlusive material 4 from the lumen 2. Finally, the flow restorationmember 14 and the engaged occlusive material 4 is pulled back into thelumen 22 of the catheter 12 and the system 10 is withdrawn from thepatient.

In one embodiment of the present invention, as shown in FIGS. 5-7, theocclusion management system 10 may further employ an extraction member38 for extraction or removal of the occlusive material 4, such as anembolus. The extraction member 38 may have an umbrella-likeconfiguration, as shown in FIG. 5; a conical configuration, as shown inFIG. 6; or a cup-like configuration, as shown in FIG. 7. The extractionmember 38 expands from a compressed diameter to an expanded diameterthat is greater than a diameter of the expanded flow restoration member14 and approximately equal to a diameter of the lumen 2.

The extraction member 38 may be attached directly to the flowrestoration member 14 or to a separate structure that is deployedthrough the flow restoration member 14 either before or after deploymentof the flow restoration member 14. For example, as shown in FIGS. 5 and6, a distal portion 44 of the extraction member 38 may be attached to adistal end 46 of a delivery element 42. The delivery element 42 may beformed of a separate, transposable element that is located within alumen of the pusher 16. One or more tethers 40 may statically attach aproximal periphery 48 of the extraction member 38 to the deliveryelement 42 proximally of the distal end 46 of the delivery element 42.The tethers 40 facilitate compression and retraction of the extractionmember 38 back into the catheter 12. Alternatively, the tethers 40 maybe transposable independent of the delivery element 42. For example, thetethers 40 may be attached to a coaxial tube located within the lumen ofthe pusher 16 around the delivery element 42.

In operation, the extraction member can be deployed either prior tocomplete deployment of the flow restoration member 14 or after completedeployment of the flow restoration member 14.

In certain embodiments, as shown in FIG. 25, the extraction member 38 isa balloon 56 that is attached to a distal end 46 of a delivery element42. The delivery element 42 has a lumen formed therethrough forinflation and deflation of the balloon 56. The balloon 56 having adiameter that is substantially equal to or greater than a diameter ofthe vessel 2.

In certain other embodiments, as shown in FIG. 26, the extraction member38 is formed by a malecot-type formation of the distal end 46 of thedelivery element 42. The malecot-type formation may be covered with afabric, polymer, or braided covering. The malecot-type formation has adiameter that is substantially equal to or greater than a diameter ofthe vessel 2.

In certain other embodiments, as shown in FIG. 29 the extraction member38 is formed of a braided structure having a disc-like form that isattached to a distal end 46 of a delivery element 42. The disc-likestructure has a diameter that is substantially equal to or greater thana diameter of the vessel 2.

In one embodiment of the present invention, as shown in FIG. 7, thedelivery element 42 is not employed in the system 10 and extractionmember 38 is attached directly to the flow restoration member 14 by thetethers 40. More particularly, proximal ends of the tethers 40 areattached to the distal portion 34 of the flow restoration member 14 anddistal ends of the tethers 40 are attached to the proximal periphery 48of the extraction member 38.

In operation, after the catheter 12 is advanced through the occlusivematerial 4 until a distal end 24 of the catheter 12 passes entirelythrough the occlusive material 4, the catheter 12 is then retractedrelative to the pusher 16. As the extraction member 38 is exposed fromthe retracting distal end 24 of the catheter 12, the extraction member38 radially expands distally of the occlusive material 4. As thecatheter 12 is further retracted, the flow restoration member 14radially expands within the occlusive material 4.

After complete expansion of the flow restoration member 14, the pusher16 is retracted relative to the catheter, thereby pulling the flowrestoration member 14 through the occlusive material 4 and pulling theextraction member 38 into and around the occlusive material 4. Theocclusive material 4 is thereby captured within the extraction member38. Retraction of the pusher 16 is continued until the flow restorationmember 14 and extraction member 38 with captured occlusive material 4are pulled back into the lumen 22 of the catheter 12. The system 10 isthen withdrawn from the patient.

The extraction member 38 may be formed at least in part by a braid offilaments or fabricated by methods known in the art of stentmanufacturing including but not limited to conventional machining, lasercutting, electrical discharge machining (EDM) and photo-chemicaletching.

In one embodiment of the present invention, as shown in FIGS. 8-11 , theflow restoration member and the extraction member of the occlusionmanagement system 100 are formed of a substantially continuousstructure. For example, as shown in FIG. 10, a distal portion 134 of aflow restoration member 114 is biased to evert to a relaxed state thatturns in a proximal direction back towards a proximal portion 120 of theflow restoration member 114, thereby forming an extraction member 138.One or more tethers 140 are eccentrically coupled or attached to thedistal portion 134 of a flow restoration member 114. In certainembodiments, a radially expandable connector member 150 may hold ends ofthe filaments that may be present at the distal portion 134 of a flowrestoration member 114.

Proximal ends of the tethers 140 may extend proximally within the lumen22 of the catheter 12 and may be manipulated by a physician in order tofacilitate the formation of the everted distal portion 134 andextraction member 138 of the flow restoration member 114. In certainembodiments, the tethers 140 do not extend to a proximal end of thesystem 100 but rather are connected to an elongate retraction memberthat in turn extends proximally for manipulation by a physician. Asshown in FIG. 10, the tethers 140 may further function to cut throughthe occlusive material 4 as the extraction member 138 is formed or whenthe pusher 16, the flow restoration member 114, and the extractionmember 138 are retracted relative to the catheter 12.

In certain embodiments, as shown in FIG. 27, the flow restoration member114 having everted distal portion 134 need not necessarily employ thetethers 140.

In certain other embodiments, as shown in FIGS. 21 -24, 28A, and 28B,the mesh or scaffold structure forming the flow restoration member 114employs an enlarged diameter distal portion 134 that does notnecessarily evert. For example, FIG. 21 shows a partially deployed andFIG. 23 shows completely deployed flow restoration member 114 having aflared or expanded distal portion 134. FIG. 24 shows the flowrestoration member 114 having a bulbous, expanded distal portion 134which may or may not employ a guide wire passage through a distal end.

In certain other embodiments, as shown in FIG. 28A and 28B, theextraction member 38 is a wireform attached to the delivery element,such as delivery element 42 described above, or alternatively attacheddirectly to the flow restoration member 114 to form an expanded distalportion 134 of the flow restoration member 114. The wire form may alsobe covered with a braid. As shown in FIGS. 8-11, operation of theocclusion management system 100 is substantially the same as describedabove regarding the occlusion management system 10 employing theextraction member 38.

In one embodiment of the present invention, as shown in FIG. 12, thepusher 16 may be formed of a wire, tube, or catheter.

In one embodiment of the present invention, as shown in FIGS. 13-19, amethod for operation of system 10, 100 is shown. First, retrieval ofocclusive matter 4 includes first advancing a guidewire 6 through alumen 2 to the site of the occlusive material 4 and through theocclusive material 4. The catheter 12 is then advanced over theguidewire 6 to the site of the occlusive material 4 and through theocclusive material 4, as shown in FIGS. 13 and 14. The guidewire 6 iswithdrawn from the patient. As shown in FIG. 15, the catheter 12 is thenretracted relative to the pusher 16, thereby allowing the flowrestoration member 14 to expand to a more relaxed state and engage theocclusive material 4.

In certain embodiments, as shown in FIG. 17, the catheter 12 may bepassed through a lumen of a sheath 8. The sheath 8 may function toprovide suction, vacuum, or irrigation, in the direction of arrows 26,within the lumen 2 near the site of the occlusive material 4.Alternatively, as shown in FIG. 18, one or more holes 52 may be formedin the catheter 12 so that the suction, vacuum, or irrigation mayoriginate from a proximal end of the catheter 12 and be simultaneouslygenerated through the proximal portions of both the lumen 22 of thecatheter 12 and the lumen of the sheath 8.

With the assistance of such suction, vacuum, or irrigation, as shown inFIG. 19, it may be possible for the flow restoration member 14 tosufficiently engage the occlusive material 4 such that the occlusivematerial 4 is released from the lumen 2 and can be extracted insubstantially its entirety from the lumen 2 of the patient.

In one embodiment of the present invention, as shown in FIG. 20, inorder to further assist in the generation and efficacy of such suction,vacuum, or irrigation, an annular balloon 54 may be attached to anexterior of the catheter 12 near the distal end 24 of the catheter 12.The balloon 54 is sized so as to contact a circumference of an interiorsurface of the lumen 2. Accordingly, the balloon 54 provides a sealagainst the flow of fluid, such as blood, through the lumen 2 andenhances the efficacy of the suction, vacuum, or irrigation. FIG. 22shows the flow restoration member 114 of FIG. 23 being deployed througha catheter 12 having an inflated balloon 54 near the distal end 24 ofthe catheter 12. In order to inflate and deflate the balloon 54,inflation lumens may be formed within the wall of the catheter 12according to techniques known in the art.

In one embodiment of the present invention, as shown in FIGS. 30-35, anocclusion management system 200 employs a flow restoration member 214,such as that described above with respect to the flow restorationmembers 14 or 114 that is advanceable through a proximal capture member260.

The proximal capture member 260 is radially expandable from compresseddelivery state within a lumen 258 of a sheath 208, to a radiallyexpanded, minimum energy state having a generally cylindrical or tubularshape. When in the expanded minimum energy state, the proximal capturemember 260 may have a diameter that is larger or substantially equal tothe diameter of the patient's lumen 2 in which the system 200 will beemployed.

The proximal capture member 260 is attached to a capture member pusher262 that is also inserted through the lumen 258 of the sheath 208. Theproximal capture member 260 may be formed of a mesh or scaffold. Themesh or scaffold may be formed at least in part by a braid of filamentsor fabricated by methods known in the art of stent manufacturingincluding but not limited to conventional machining, laser cutting,electrical discharge machining (EDM) and photo-chemical etching.

The flow restoration member 214 is attached to the pusher 16 and theflow restoration member 214 and the pusher 16 are positioned within thelumen 22 of the catheter 12. The catheter 12 is, in turn, positionedwithin a lumen of the proximal capture member 260. A diameter of theproximal capture member 260 may be approximately equal to or greaterthan a diameter of the lumen 2.

In operation, the capture member pusher 262 and attached proximalcapture member 260 are inserted into the lumen 258 of the sheath 208. Aguidewire may be advance through the occlusion material 4, such as athrombus or embolus. The sheath 208 is then advanced over the guidewireto a position proximal of the occlusion material 4. The guidewire maybut need not necessarily be retracted at this time.

As shown in FIGS. 30 and 31, the sheath 208 is retracted, in thedirection of arrow 28, proximally relative to the capture member pusher262, thereby exposing the proximal capture member 260 at a distal end266 of the sheath 208 and allowing the proximal capture member 260 toradially expand from its collapsed state within the lumen 258 of thesheath 208.

The pusher 16 and attached flow restoration member 214 are then insertedinto the lumen 22 of the catheter 12. As shown in FIG. 32, the catheter12 is then advanced through the lumen 258 of the sheath 208 and thelumen of the proximal capture member 260 until a distal end 24 of thecatheter 12 is positioned distally of the occlusive material 4. As shownin FIGS. 33 and 34, the catheter 12 is then retracted, in the directionof arrow 28, proximally relative to the flow restoration member 214,thereby exposing the flow restoration member 214 and allowing the flowrestoration member 214 to radially expand from its collapsed statewithin the lumen 22 of the catheter 12.

As shown in FIG. 35, after complete expansion of the flow restorationmember 214, the pusher 16 is retracted relative to the catheter 12,thereby pulling the flow restoration member 214 through the occlusivematerial 4 and pulling an extraction member, if present, into and aroundthe occlusive material 4. The occlusive material 4 is thereby capturedwithin the flow restoration member 214 and extraction member, ifpresent. Retraction of the pusher 16 is continued until the flowrestoration member 214 and extraction member, if present, with capturedocclusive material 4 are pulled at least partially back into the lumen22 of the catheter 12. The catheter 12 and the flow restoration member214 and extraction member, if present, with captured occlusive material4 are then pulled back into the lumen 264 of the proximal capture member260. The proximal capture member 260 is then pulled back into the lumen258 of the sheath 208. The system 200 is then withdrawn from thepatient.

The order of deployment of the proximal capture member 260 and flowrestoration member 214 as described above may be reversed as seen fit bythe physician. Furthermore, therapeutic agent(s) such as thrombolyticsor anticoagulants may be infused through the lumen 258 of the sheath 208or lumen 22 of catheter 12 during the course of the procedure.

In one embodiment of the present invention, the occlusion managementsystems 10, 100, 200 is configured for removal of at least a portion ofthe occlusive material 4, such as an embolus or thrombus, that islocated at a bifurcation, trifurcation or multi-lumen plexus of thelumen 2, such as a blood vessel. By way of example, as shown in FIGS. 36and 37, a sheath 8, through which multiple catheters 12 are inserted, isadvanced through the lumen 2 to the bifurcation at which occlusivematerial 4 is present. The catheters 12 are independently advanceddistally from the sheath 8 through the occlusive material 4 within thedifferent lumens 2 of the bifurcation. Flow restoration and extractionof the occlusive material 4 is conducted as described above.

In certain embodiments of the present invention, the flow restorationmember 14, 114, 214, extraction member 38, 138, and the proximal capturemember 260 may comprise a braided mesh of filaments or wires 70. Thebraids for the mesh components may have a generally constant braid angleover an entire length of the member or may be varied to providedifferent zones of pore size and radial stiffness.

The braided mesh may be formed over a mandrel as is known in the art oftubular braid manufacturing. A braid angle a (alpha), shown in FIG. 38,may be controlled by various means known in the art of filamentbraiding. In certain embodiments, the braid angle a is, for example,between about 45 degrees and about 60 degrees. The tubular braided meshmay be further shaped using a heat setting process. As known in the artof heat setting nitinol wires, a fixture, mandrel or mold may be used tohold the braided tubular structure in its desired configuration thensubjected to an appropriate heat treatment such that the resilientfilaments of the braided tubular member assume or are otherwiseshape-set to the outer contour of the mandrel or mold.

In certain embodiments, the filamentary elements of the mesh member maybe held by a fixture configured to hold the member in a desired shapeand heated to about 475-525 degrees Celsius for about 5 to 30 minutes toshape-set the structure. In certain embodiments, the braid may be atubular braid of fine metal wires 70 such as Nitinol, platinum,cobalt-chrome alloys, 35N LT, Elgiloy, stainless steel, tungsten ortitanium.

In certain embodiments, the member can be formed at least in part from acylindrical braid of elastic filaments. Thus, the braid may be radiallyconstrained without plastic deformation and will self-expand on releaseof the radial constraint to an unrestrained diameter or diameter at itslowest energy state. Such a braid of elastic filaments is hereinreferred to as a “self-expanding braid.”

In certain embodiments, the thickness of the braid filaments is lessthat about 0.5 millimeters. In certain embodiments, the braid may befabricated from wires 70 with diameters ranging from about 0.015millimeters to about 0.40 millimeters. In certain embodiments, the braidmay be fabricated from wires with diameters ranging from about 0.02millimeters to about 0.15 millimeters.

In certain embodiments, the member has a high braid angle zone where thebraid angle a is greater than about 60 degrees. More particularly, thehigher braid angle portion or zone may have a braid angle a that isbetween 60 and 80 degrees. The high braid angle portion may have higherradial stiffness that may provide, for example, improved extraction ofocclusive material 4. Furthermore, as the member is retracted theportion of the member with a high braid angle elongates to a greateramount relative to the remainder of the member, thereby providing alonger surface for retraction through the occlusive material.

In certain embodiments, the system may comprise a braided member wherethe braid is formed from a mixture of more than one diameter wire 70, asshown in FIG. 38. A braid showing two wire diameters, wire 70 a andwires 70 b having a smaller diameter than the diameter of the wires 70a, is shown in FIG. 39.

A braided member may also comprise a plurality of layers. In certainembodiments, the system may comprise a braided member where the braidconfiguration changes over the length of the member forming a tubularstructure with two or more zones of different braid. The parameters thatmay be changed to manipulate the braid include but are not limited tobraid angle a, combinations of different diameters of wire 70 (e.g. acombination of small and large diameters) and wire loading (e.g.alternating wire size in a 1 by 1 or 2 by 2 pattern). Changing the braidparameters allows for zones of different mechanical properties (e.g.radial stiffness and compliance) along one continuous braid. In certainembodiments, the member may have one zone with a braid angle a betweenabout 35 degrees and 55 degrees and another zone with a braid angle abetween about 50 degrees and 70 degrees. In certain embodiments, themember may have one zone with a radial stiffness that is at least about25% greater than the radial stiffness of a second zone.

In one embodiment of the present invention, as shown in FIGS. 40A-40C,the flow restoration member may be formed by machining or laser cuttinga stent-like pattern either directly in a tube or in a flat sheet thatis subsequently formed into a tube. The sheet may be rolled or otherwiseformed into a generally tubular configuration and then welded, solderedor joined in order to fix the tubular shape. FIG. 40A shows an exemplaryflat pattern. FIG. 40B shows the tube form of the stent-like pattern andFIG. 40C shows the stent-like tube attached to the distal end of apusher or delivery element. In certain other embodiments, as shown inFIG. 27, the extraction member 138 is a braided structure extension offlow restoration member 114 that has been everted and curled back onitself forming an expanded distal portion. In any of the above describedembodiments, the system 10, 10, 200 may include additional devices orcomponents to facilitate thrombus maceration or disruption including butnot limited to mechanical maceration members (auger, drill bit, screw,impellor, burr, pick, etc.), vibration members, ultrasonic energy,radiofrequency energy, microwave energy, thermal energy, cavitiation,flow jets or perfusion apparatus. For example, in certain embodiments,the system 10, 100, 200 may comprise a boring member to facilitatepenetration of the occlusive material 4. In certain embodiments, thesystem 10, 100, 200 may comprise an auger device to facilitateretraction of the occlusive material 4, such as thrombus along a centralpath coaxial with the flow restoration member 14, 114, 214.

In any of the above described embodiments, the system 10, 100, 200 mayinclude a drug or bioactive agent to enhance the thrombus extractionperformance and/or reduce the propensity to produce clotting. In certainembodiments, the system 10, 100, 200 and more particularly the flowrestoration member 14, 114, 214, extraction member 38, 138, and theproximal capture member 260 may employ textures, surface features,coatings, or the like to enhance the engagement and/or attachment of theocclusive material 4, such as thrombus. In certain embodiments, thedevice may include an antiplatelet agent, a lytic agent or ananticoagulant.

In any of the above described embodiments, a delivery system may beprovided or integrated into the catheter 10 and/or sheath 8, 208. Thedelivery system may include an introducer sheath for access into theappropriate vein such as the subclavian vein, jugular vein, femoral veinor radial vein. In certain embodiments, the catheter 10 and/or sheath 8,208 may be placed through the introducer sheath to pass through theaccess vein such as the right subclavian vein or jugular vein into thesuperior vena cava through the right atrium through the tricuspid valve,through the right ventricle, through the pulmonic valve, to thrombus orocclusive embolus situated in the pulmonary artery or branches of thepulmonary artery. In some embodiments, the catheter 10 and/or sheath 208may be placed through the introducer sheath to pass through the accessvein such as the femoral vein into the inferior vena cava through theright atrium through the tricuspid valve, through the right ventricle,through the pulmonic valve, to thrombus or occlusive embolus situated inthe pulmonary artery or branches of the pulmonary artery.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. An occlusion management system comprising: acatheter having an elongate shaft defining a first lumen; a pusherhaving a proximal end and a distal end, wherein the pusher is coaxialthe first lumen; a self-expanding scaffold member formed of a tubularfenestrated structure with an open proximal end having a perimeter andan open distal end; and a capture member formed of a braided mesh andhaving a proximal end attached to the pusher, an everted distal portion,and a distal end attached to the perimeter of the proximal end of thescaffold member.
 2. The occlusion management system of claim 1, whereinthe capture member is self-expanding.
 3. The occlusion management systemof claim 2, wherein the distal end of the capture member is biased toevert in a relaxed state.
 4. The occlusion management system of claim 1,wherein the scaffold member and the capture member form a continuousstructure.
 5. The occlusion management system of claim 1, wherein adiameter of the distal end of the capture member is no larger than adiameter of the proximal end of the scaffold member.
 6. The occlusionmanagement system of claim 1, further comprising a control featurecontrollably coupled to the distal end of the scaffold member throughthe first lumen of the catheter, wherein the control feature ismanipulable to control the formation of the everted distal portion ofthe scaffold member.
 7. The occlusion management system of claim 6,wherein the control feature is controllably coupled to the distal end ofthe scaffold member via an elongate retraction member.
 8. The occlusionmanagement system of claim 7, wherein a portion of the capture memberextends proximally through scaffold member.
 9. A method for removal ofthrombus from a peripheral blood vessel in a body of a patient, themethod comprising: providing a thrombus extraction device thrombusextraction device comprising a scaffold member formed of a tubularfenestrated structure with an open proximal end having a perimeter andan open distal end, a proximal capture member formed of a mesh structurewhich is attached to the proximal end of the scaffold member, and apusher connected to a proximal end of the mesh structure; advancing acatheter constraining the thrombus extraction device through thethrombus located in the peripheral vasculature of a patient's body;deploying the thrombus extraction device, wherein the deployed thrombusextraction device comprises an everted distal portion of the capturemember, and wherein deploying the thrombus extraction device comprisesexpanding the scaffold member and expanding the everted distal portionof the capture member; retracting the thrombus extraction device tocapture thrombus within an everted distal portion of the capture member;and withdrawing the thrombus extraction device from the body of thepatient.
 10. The method of claim 9, wherein deploying the thrombusextraction device further comprises everting a distal portion of thecapture member.
 11. The method of claim 10, wherein the distal end ofthe capture member is biased to evert in a relaxed state.
 12. The methodof claim 9, wherein retracting the thrombus extraction device into thecatheter constrains the thrombus extraction device and the capturedthrombus within the catheter.
 13. An occlusion management systemcomprising: a catheter having an elongate shaft defining a first lumen;a pusher having a proximal end and a distal end, wherein the pusher iscoaxial the first lumen; a self-expanding scaffold member formed of atubular fenestrated structure with an open proximal end coupled to thedistal end of the pusher and with an open distal end having a perimeter;and a tapered capture member formed of a braided mesh and having aproximal end attached to the perimeter of the distal end of the scaffoldmember.
 14. The occlusion management system of claim 13, wherein adiameter of the proximal end of the capture member is no larger than adiameter of the distal end of the scaffold member.
 15. The occlusionmanagement system of claim 13, wherein the capture member is aself-expanding braid.
 16. The occlusion management system of claim 13,wherein the expansion of the capture member is controllable independentof the expansion of the scaffold member.
 17. The occlusion managementsystem of claim 13, wherein the perimeter of the open distal end of thescaffold member in an expanded configuration is circular.
 18. Theocclusion management system of claim 13, wherein the scaffold member andthe capture member form a continuous structure.
 19. A method for removalof thrombus from a peripheral blood vessel in a body of a patient, themethod comprising: providing a thrombus extraction device thrombusextraction device comprising a scaffold member formed of a tubularfenestrated structure with an open proximal end having a perimeter andan open distal end, a tapered capture member formed of a mesh structurewhich is attached to the distal end of the scaffold member, and a pusherconnected to a proximal end of the scaffold member; advancing a catheterconstraining the thrombus extraction device through the thrombus locatedin the peripheral vasculature of a patient's body; deploying thethrombus extraction device, wherein the deploying the thrombusextraction device comprises expanding the scaffold member; retractingthe thrombus extraction device through the thrombus; separating thethrombus from the peripheral blood vessel with the scaffold member; andcapturing the thrombus within the tapered capture member.
 20. The methodof claim 19, further comprising withdrawing the thrombus extractiondevice from the body of the patient.
 21. The method of claim 19, whereinthe deploying the thrombus extraction device comprises expanding thetapered capture member.
 22. The method of claim 19, wherein thedeploying the thrombus extraction device comprises expanding the taperedcapture member subsequent to expanding the scaffold member.
 23. Themethod of claim 19, wherein the deploying the thrombus extraction deviceretracting the catheter relative to the pusher until the scaffold memberis exposed.
 24. The method of claim 19, wherein retracting the thrombusextraction device through the thrombus comprises retracting the pusherrelative to the catheter through a lumen of the catheter.